The present invention relates to a new organic electroluminescence device; a thin-film, light-weight and high definition organic electroluminescence device; new photoelectron devices using said devices, such as a thin-film flat panel display, small sized portable projection display, cellular phone display device, portable PC display, real-time electronic bulletin board, light emitting diode, laser, two-dimensional optical pattern generating device, optical computer, optical cross connector and optical router; as well as to the systems and services using them.
There has been a growing demand for a light-weight, high definition and less costly small-sized flat panel display for use in the various types of cellular phones, mobile terminals, mobile computers and car navigation systems being developed. For household and office use, a space saving desktop display, a flat panel display and wall-mounted TV sets are taking the place of conventional CRT tube displays. Especially, digital signal transmission on the order of hundreds to several gigabits/sec. has been put into commercial use in both wired and wireless methods, as a result of the increased use of the high-speed Internet and the progress of digital broadcasting. Time is shifting into an age where general users will exchange a huge amount of information on a real-time basis. Under these circumstances, flat panel displays are required to provide a higher speed display to permit digital processing, in addition to being still more light-weight, and having a higher definition, a higher luminance and a lower price.
The Liquid Crystal Display (LCD), Plasma Display (PD) and Field Emission Display (FED) are currently under study to meet these requirements. In addition to these flat panel displays, new types of flat panel display, referred to as Organic Electroluminescence Devices (OELD) or Organic Light Emitted Diodes (OLED), have begun to draw attention in recent years.
The organic electroluminescence device provides a method of causing fluorescent or phosphorescent organic molecules to emit light by allowing an electric current to flow to the organic compound sandwiched between a cathode and an anode, thereby displaying information. According to the References (xe2x80x9cMajor Issues of Organic LED Elements to be Solved and Practical Statisticsxe2x80x9d edited by the Organic Electronics Material Research Organization, Bunshin Publishing Co., mid-1999, P.1-11, and xe2x80x9cPreface to Current Situation and Issues of Materials and Devicesxe2x80x9d by Yoshiharu SATO), organic electroluminescence devices have long been studied mainly with respect to semiconducting crystals, such asanthracene and perylene.
In 1987, Tang et. al. proposed a two-layered organic electroluminescence device laminated with a light emitting organic compound thin film and a hole transporting organic compound thin film (C. W. Tang and S. A. Van Slyke, Appl. Phys. Lett. 51, 913 in 1987). The starting point is that a dramatic improvement of light emitting characteristics is enabled (light emitting efficiency: 1.51 m/W, drive voltage; 10V and luminance: 1000 cd/m2). Since then, a pigment doping technique and high molecular OLED, low working function electrode, mask vacuum evaporation system, etc. have been studied.
In 1997, an organic electroluminescence device based on an electrical charge injection method, called a simple matrix system was partly put into commercial use. Further, a new organic electroluminescence device based on the electrical charge injection method, called an active matrix system is currently under study for development. Such an organic electroluminescence device is operated according to the following principle: A fluorescent or phosphorescent organic light emitting material is made into a thin film between a pair of electrodes, and electrons and holes are injected from positive and negative electrodes. In the organic light emitting material, the injected electron becomes an organic one-electron molecule (simply called an electron) entering the Lowest Unoccupied Molecular Orbital (LUMO) of a light emitting molecule. The injected hole becomes an organic one-hole molecule (simply called hole) entering the Highest Occupied Molecular Orbital (HOMO) of the light emitting molecule. In the organic material, they move toward the opposite electrode. In the middle of the movement, when an electron meets a hole, a singlet or triplet state of excitation of the light emitting molecule is formed. As it deactivates while radiating light, light is released.
Generally, many of the organic light emitting materials are those having a high quantum efficiency with respect to photoexcitation, as in the case of various laser pigments. If these materials are made to emit light by electrical charge injection, the electron and hole have a lower electrical charge transport performance since many organic compounds are insulators. A high voltage on the order of hundreds of volts was required in the initial organic electroluminescence device. However, using excellent electrical charge transporting performances of the organic electrophotographic photoconductor used as a photoconductor of a copying machine, a thin film is divided into two types according to function. One is the film used to transport an electrical charge (hole), and the other is the film used to emit light. This separation of functions of the thin films has improved the light emitting characteristics in the above-mentioned Tang""s two-layered organic electroluminescence device.
Recently, a 3-layered organic electroluninescence device has been reported wherein the electron transport performance of another electrical charge is assigned to a third organic thin film. In addition, separated function type and multi-layered film type organic electroluminescence devices have been proposed, wherein thin films assigned to perform various functions are added; for example, an electrical charge injection layer is provided to improve the characteristics of injecting the hole and electron into the organic material and a hole stop layer to improve the probability of re-combination between the two. However, the basis for light emitting is light radiation in the process of deactivation in the state of excitation from the organic light emitting molecule contained in the organic light emitting layer. This basis remains unchanged.
According to the References (xe2x80x9cMajor Issues of Organic LED Elements to be Solved and Practical Statisticsxe2x80x9d edited by the Organic Electronics Material Research Organization, Bunshin Publishing Co., mid-1999, P.25-38, and Yuuji HAMADA, xe2x80x9cChapter 2. Current situation and issues of Light Emitting Materialxe2x80x9d), a great number of the fluorescent or phosphorescent organic light emitting materials are known to have been developed for a variety of purposes, such as ink, dye and scintillator materials. The organic electroluminescence devices are made of these organic light emitting materials. They can be broadly classified in terms of molecular weight into low molecular and high molecular types.
The low molecular type is formed into thin films according to a dry process, such as a vacuum evaporation method, while the high molecular type is formed into thin films according to the cast method. Failure in the formation of organic thin films is said to be one of the reasons why a highly efficient device could not be obtained as an organic electroluminescence device in earlier days before Tang. Conditions required especially for the low molecule type are as follows: (1) Production of a thin film (100 nm level) in the vacuum evaporation system, (2) maintainability of a uniform thin film structure after formation of the film (without segregation crystal), (3) fluorescent light quantum yield in the solid status, (4) appropriate carrier transport performance, (5) heat resistance, (6) easy refining, and (7) electrochemical stability, etc. Further, this type can be classified into two types according to the light emitting process, that is, the light emitting material where light is emitted by direct re-combination between electron and hole, and fluorescent material (or dopant material) where light is emitted by photoexcitation caused by the light emitting material. In addition, when viewed from the differences in chemical structure, the following materials are known; metallic complex type light emitting material (8-quinolinol, benzooxazol, azomethine, flavone, etc. as ligand, and Al, Be, Zn, Ga, Eu, Pt, etc. as central metal) and fluorescent pigment based light emitting material (oxadiazole, pyrazoline, distyryl arylene, cyclopentadiene, tetraphenyl butadiene, bisstyryl anthoracene, perylene, phenanthrene, oligothiophene, pyrazoloquinoline, thiadiazopyridine, laminated perovskite, p-sexiphenyl, spiro compound, etc.).
As described above, a great variety of materials and techniques have been studied on the light emitting material and device production process of the organic electroluminescence device. However, these studies have not yet completely clarified the efficiency where the amount of light can be emitted from such an organic electroluminescence device. According to the References (xe2x80x9cMajor Issues of Organic LED Elements to be Solved and Practical Statisticsxe2x80x9d edited by the Organic Electronics Material Research Organization, Bunshin Publishing Co., mid-1999, P.105-118, and xe2x80x9cChapter 1 Interpretation and Limit of Light Emitting Efficiencyxe2x80x9d by Tetsuo IZUTSU), optical energy taken out of the organic electroluminescence device is given in terms of the number of photons released for each of electrons or holes running through the device. If this is expressed in terms of external quantum efficiency of electroluminescence xcex7xcfx86(ext), the following relationship is known to hold:
xcex7xcfx86(ext)=xcex7extxc3x97xcex7xcfx86(int)=xcex7extxc3x97[xcex3xc3x97xcex7rxc3x97xcex7f]xe2x80x83xe2x80x83(1)
where xcex7xcfx86(int) is an internal quantum efficiency representing the number of photons released for each of the electrons or holes running through the device inside the device, and xcex7xcfx86(ent) denotes the efficiency of discharging, out of the device, the light produced inside the device after having been reduced by reflection or absorption on the device boundary. xcex3 shows the charge balance equivalent to the ratio of the numbers of the electrons and holes injected inside the device, and xcex7r indicates the singlet exciton generation efficiency denoting the ratio of emitting the i-term exciton contributing to light emitted from the injected electric charge. xcex7f denotes light emitting quantum efficiency representing the ratio of emitting light and deactivating in the singlet exciton.
The external quantum efficiency xcex7xcfx86(ext) equivalent to the amount of light emitted out of the device can be broadly classified into three, that is, xcex7r and xcex7f determined by the properties of the light emitting material itself, xcex3 determined by the ratio of injecting the electrons and holes into the device, and xcex7(ext) determined by the device structure. xcex7r and xcex7f are efficiencies related to the physical properties of the light emitting material itself and are uniquely determined by the light emitting material. xcex3 is the amount determined by the electrical potential difference between the electrode and organic layer adjacent thereto, the boundary potential and the ease of movement of the electrons and holes in the organic layer. It is an efficiency uniquely determined by the physical properties of the electrode material and device internal organic material. Of these factors, the charge balance xcex3xe2x89xa61. The singlet exciton generation efficiency xcex7r is said to be the electrical charge spin xcex7rxe2x89xa60.25. Light emitting quantum efficiency xcex7r less than 1 except in the super-radioactive process. Therefore, the portion of the factor determined by the organic material inside the device and electrode material (the portion [xcex3xc3x97xcex7rxc3x97xcex7f] in Formula (1)) is said to be 0.25 or less. On the other hand, according to the Reference (Greenham, R. H. Friend, D. D. C. Bradley. Adv. Mater. 6, 491 in 1994), the discharge efficiency is determined by the reflection and refraction of classical optics. Assuming that the refractive index of the light emitting layer is xe2x80x9cnxe2x80x9d, it is given by the following equation:
xcex7ext=1/(2n2)xe2x80x83xe2x80x83(2)
The refractive index of the light emitting layer of many organic electroluminescence devices or the glass substrate holding them is about 1.6. Thus, xcex7ext=0.2. From the above discussion, the external quantum efficiency of the external electroluminescence is xcex7xcfx86(ext)xe2x89xa60.2xc3x970.25=0.05, and the external quantum efficiency is said to be 5% at most.
To put the organic electroluminescence device to commercial use, it is essential to improve the external quantum efficiency. The external quantum efficiency of the above-mentioned conventional organic electroluminescence device has an upper limit, so the development of an organic electroluminescence device having different functions is currently under way. One of the methods is to improve the light emitting quantum efficiency singlet exciton generation efficiency xcex7r of the light emitting material itself. In the conventional charge injection and re-combination process, singlet exciton occurs at the ratio of 0.25, and triplet exciton occurs at the ratio of 0.75. By contrast, the triplet exciton is converted to a singlet exciton by spinning in a reverse direction through an inter-item intersection resulting from the spin/orbital angular moment interaction of the organic light emitting material containing heavy metal, or the triplet exciton that has occurred is converted into a singlet exciton through mutual collision of triplet excitons enclosed in the nano-level range, thereby increasing the ratio of the exciton making contribution to light emission. As the material having such a new exciton generation mechanism, an organic electroluminescence device capable of high-efficiency light emission through the use of fac tris(2-phenylpyridine)iridium [Ir(ppy)3] is introduced in Reference (M. A. Baldo, S. Lamansky, P. E. Burrows, M. E. Thompson, and S. R. Forrest, Appl. Phys. Lett. 75, 4-6 in 1999).
Another method is intended to improve the external quantum efficiency outside the device by improving the discharge efficiency xcex7ext. Namely, a uniform thin film structure without crystal segregation has been considered essential for the production of the organic electroluminescence device. In this case, the organic light emitting material constituting the light emitting layer is random-oriented in terms of space. So light has been emitted isotrophically in all directions inside the device. By contrast, a means of controlling the light emitted in the direction parallel to the light emitting surface of the device and increasing the light emitted in the vertical direction is described in the Reference (Japanese Patent Laid-Open 40413/1992) which discloses an organic electroluminescence device having a light emitting layer comprising molecules uniaxially oriented, for example, by the rubbing method.
According to the Reference (Japanese Patent Laid-Open No. 102783-1999), in the organic electroluminescence device produced by forming a light emitting layer in the dry process in a vacuum and by orienting the organic molecules constituting the light emitting layer parallel to the light emitted surface by photoisomerization reaction, an anisotropic light emitting characteristic was similarly obtained inside the light emitting layer. However, improvement of the discharge efficiency by orientation is not specifically described in these References. Only the Reference (Japanese Patent Laid-Open NO. 102783/1999) describes that light emitting efficiency outside the device was improved about 1.6 times from 0.51 m/W to 0.8 m/W.
In the earlier Reference (M. Hamaguchi and K. Yoshino, Jpn, J. AppI. Phys. Vol. 34, P. L712, in 1995), detailed measurements were made on the light emitting anisotropy and discharge efficiency of the oriented organic electroluminescence device. According to FIG. 1 thereof, a remarkable difference in the amount of light to be discharged is observed in the direction parallel to the orientation and the direction vertical thereto. By contrast, no marked difference in the amount of the discharged light is observed between the oriented sample and non-oriented sample.
As described above, methods of improving the light emitting efficiency over the previous level are being studied for the organic electroluminescence device. Since many such factors are included, no definite guideline has been established as yet.
To put such an organic electroluminescence device into practical use, it is essential to improve the external quantum efficiency. There is an upper limit to the external quantum efficiency of the above-mentioned conventional organic electroluminescence device. One of the methods is to improve the singlet exciton generation efficiency xcex7r of the light emitting quantum efficiency of the light emitting material itself, and to improve the external quantum efficiency outside the device by improving the discharge efficiency xcex7ext. Of these, the latter proposal is associated with the improvement of discharge efficiency xcex7ext. It is intended to provide a more extensive efficiency improvement.
Namely, when the discharge efficiency of the conventional organic electroluminescence device was analyzed, isotrophic light emission inside the light emitting layer was the basis for logical analysis. Improvement of discharge efficiency was suggested when molecules were oriented uniaxially or in parallel to the light discharge plane. But there was no clear description of the specific degree of orientation, its orientation or the correlation between the related direction of light emission and the structural orientation direction of the molecules. Therefore, the relationship between the molecule orientation direction and orientation direction to provide the optimum discharge efficiency was not necessarily clear. For this reason, it was not possible to perform absolute quantitative design regarding the obtained spatial orientation for light emission.
Furthermore, systematic and concrete study has not been made to clarify the relationship among the polarization and double refraction of the light emitting component itself caused by forming the state of anisotropic light emission, changes in the ease of movement of related electrons and holes, and the state of the boundary between the device and the outside of the device to discharge their light emitting characteristics out of the device in the final phase. In addition, no study has been made on the relationship with various intermediate layers existing between the light emitting layer and device boundary. The impact of these factors upon the emission spectrum distribution has not been studied. For this reason, no sufficient achievement has been made in terms of improvement of the external quantum efficiency based on the discharge efficiency improvement technique of conventional devices.
A control method by a fine resonator having a resonance length on the order of a wavelength is known as a orientation control means for an emission pattern. For example, the Reference (S. Tokito, Y. Taga and T. Tsutsui, Synthetic Metals, Vol 91, P. 49, 1997) includes a report on a fine resonator structure type organic electroluminescence device where tris(8-quinolinolato) aluminum (Alq3) is used as a light emitting material, and MgAg is employed for the electrode cum reflector on the back side, ITO for the electrode on the light discharge side, and (SiO2/TiO2) derivative multi-layered film for the translucent mirror on the light discharge side. FIGS. 3 and 4 show that the directivity of the emission pattern is improved by the introduction of a fine resonator structure. When the light intensity is xe2x80x9c1xe2x80x9d on the front of the light emitting device, the radiation angle where the light intensity is reduced to a half is about 60xc2x0 when there is no fine resonance structure. By contrast, the light intensity is reduced to about 20xc2x0 when a fine resonance structure is used, according to this Reference. However, in this method, the directivity of radiation differs according to the light wavelength, and there is a big change in the spectrum depending on the angle of view. At the same time, the directivity is increased extremely. So when it is used as a display for an organic electroluminescence device, there has been a problem that the angle of the field is reduced.
Another method is disclosed in the Reference (Japanese Patent Laid-Open NO.102783/1999). According to this method, a light emitting layer is formed in vacuum by a dry process, and the organic compound molecule constituting said light emitting layer is oriented in parallel to the light emitting surface, thereby improving the light emitting efficiency. According to this report, the light emitting organic molecule is oriented randomly in three dimensions in the conventional light emitting layer, and a light emitting efficiency of about 0.2 was the limit. According to this technique, the light emitting efficiency is excellent in the direction vertical to the light emitting surface. In this case, the light emitting molecule may be randomly oriented in two dimensions within the surface parallel to the light emitting surface, according to said Reference. In this technique, however, when the light intensity on the front of the light emitting device is xe2x80x9c1xe2x80x9d, radiation angle where the light intensity is reduced to a half is still about 20xc2x0, as shown in FIG. 3, and the directivity is too high. This has been a problem.
Namely, the optimum comprehensive conditions for the device have not been proposed for the overall improvement of the characteristics in an organic electroluminescence device, such as light emitting efficiency, discharge efficiency, directivity and anisotropy.
Furthermore, there has been no proposal on the image display system and configuration method thereof using the effects specified said organic electroluminescence devices which cannot been observed in other flat panel displays, or on the method of use, for example, in video distribution services based on said system which cannot be observed in the conventional video or sound broadcasting services.
One embodiment of the present invention provides an organic electroluminescence device and photoelectron device using said device, characterized by allowing both positive and negative electrical charges to be injected and transported, allowing light to be emitted by recombination between holes and electrons generated by the positive and negative electrical charges, and comprising a light emitting substance which emits light due to re-combination contained in the organic electroluminescence device or a fluorescent substance capable of emitting a secondary light upon receipt of light from the light emitting substance.
The organic electroluminescence device is characterized in that at least one light emitting substance or fluorescent substance capable of emitting light anisotropically inside the light emitting substance layer is provided, and the majority of the transition dipole moment of the molecular skeleton related to light emission in the molecules constituting the light emitting substance or fluorescent substance is distributed at an angle from 0 to 70 deg. with respect to the direction of the normal to the light discharge plane in the layer to which the substance belongs.
The organic electroluminescence device and photoelectron device using said device is characterized in that light discharged out of the anisotropically-light emitting substance layer has a polarizing characteristic.
The organic electroluminescence device and photoelectron device using said device is characterized in that a first class intermediate layer is contained outside the anisotropically light-emitting substance layer between the layer and the boundary for discharge of light out of the organic electroluminescence device, and the refractive index of the intermediate layer of the first class is lower than that of the anisotropically light-emitting substance layer or refractive index of the fist class intermediate layer and does not exceed 1.42.
The organic electroluminescence device and photoelectron device using said device is characterized in that the thickness of the first class intermediate layer has the length greater than the wavelength of the light discharged.
The organic electroluminescence device and photoelectron device using said device is characterized in that the orientation exhibiting the maximum light intensity in the distribution of the intensity of light discharged out of the anisotropically light-emitting substance layer is located within the range from 0 to 60 deg. with respect to the normal axis of the boundary for discharging light out of the device.
The organic electroluminescence device and photoelectron device using said device is characterized in that light is anisotropically emitted from the fluorescent substance capable of emitting a secondary light upon receipt of light from the light emitting substance.
Another embodiment of the present invention provides an organic electroluminescence device and photoelectron device using said device, characterized by allowing both positive and negative electrical charges to be injected and transported, allowing light to be emitted by re-combination between holes and electrons generated by the positive and negative electrical charges, and comprising a light emitting substance which emits light due to re-combination contained in the organic electroluminescence device or a fluorescent substance capable of emitting a secondary light upon receipt of light from the light emitting substance; wherein the organic electroluminescence device and photoelectron device using said device are further characterized in that a second class intermediate layer is contained outside the light-emitting substance layer between the layer and the boundary for discharge of light out of the organic electroluminescence device, and distribution of the intensity of light discharged out of the substance layer is increased after passing through the second class intermediate layer.
The organic electroluminescence device and photoelectron device using said device is characterized in that the second class intermediate layer is capable of scattering light or diffusing the optical path.
Still another embodiment of the present invention provides an organic electroluminescence device and photoelectron device using said device, characterized by allowing both positive and negative electrical charges to be injected and transported, allowing light to be emitted by re-combination between hole and electron generated by the positive and negative electrical charges, and comprising a light emitting substance which emits light due to re-combination contained in the organic electroluminescence device or a fluorescent substance capable of emitting a secondary light upon receipt of light from the light emitting substance; wherein the organic electroluminescence device is characterized in that a third class intermediate layer is located outside the light-emitting substance layer in the direction opposite to the boundary for discharging light out of the organic electroluminescence device, and the light taken out of the substance layer to the third class intermediate layer by the third class intermediate layer is reflected.
The organic electroluminescence device and photoelectron device using said device is characterized in that the light taken out of the substance layer to the third class intermediate layer by the third class intermediate layer is reflected in a direction other than the direction of regular reflection.
A further embodiment of the present invention provides an organic electroluminescence device and photoelectron device using said device, characterized by allowing both positive and negative electrical charges to be injected and transported, allowing light to be emitted by re-combination between hole and electron generated by the positive and negative electrical charges, and comprising a light emitting substance which emits light due to re-combination contained in the organic electroluminescence device or a fluorescent substance capable of emitting a secondary light upon receipt of light from the light emitting substance; wherein the organic electroluminescence device is characterized in that the light emitting substance layer is separated by a partition having a contact surface which is not parallel to the boundary for discharging light out of the organic electroluminescence device, and the partition is formed along the height crossing the light emitting layer or is formed on a layer or substrate other than the light emitting layer.
The organic electroluminescence device and photoelectron device using said device is characterized in that the partition viewed from the discharge boundary is polygonal and at least two sides of the partition forming the polygon are parallel.
The organic electroluminescence device and photoelectron device using said device is characterized in that at least one of a pair of parallel partitions forming the polygon has a length equivalent to one fourth to two fourths of the wavelength of the emitted light.
The organic electroluminescence device and photoelectron device using said device is characterized in that the partition viewed from the discharge boundary is circular.
The organic electroluminescence device and photoelectron device using said device is characterized in that the diameter of the circular partition is equal to length equivalent to one fourth to two fourths of wavelength of the emitted light.
The organic electroluminescence device and photoelectron device using said device is characterized in that the contact surface that is not parallel to the light discharge boundary of the partition can reflect or bend the light taken out of the light emitting substance layer.
The organic electroluminescence device and photoelectron device using said device is characterized in that reflection by the partition is not regular reflection.
The organic electroluminescence device and photoelectron device using said device is characterized in that a pair of the fourth class intermediate layers becoming one or more pairs of resonator mirrors holding the substance layer in-between is contained outside the light emitting substance layer, and the distance between the pair of the fourth class intermediate layers is an integral multiple of a length equivalent to one fourth to two fourths of wavelength of the emitted light.
A still further embodiment of the present invention provides an organic electroluminescence device and photoelectron device using said device capable of allowing both positive and negative electrical charges to be injected and transported, allowing light to be emitted by re-combination between holes and electrons generated by the positive and negative electrical charges, and comprising a light emitting substance which emits light due to re-combination contained in the organic electroluminescence device or a fluorescent substance capable of emitting a secondary light upon receipt of light from the light emitting substance; wherein at least one light emitting substance or fluorescent substance capable of emitting light anisotropically inside the light emitting substance layer is provided, and the majority of transition dipole moment of the molecular skeleton related to light emission in the molecules constituting the light emitting substance or fluorescent substance is distributed at an angle from 0 to 70 deg. with respect to the direction of the normal to the light discharge plane in the layer to which the substance belongs.
The organic electroluminescence device is further characterized in that a second class intermediate layer is contained outside the anisotropically light-emitting substance layer between the layer and the boundary for discharge of light out of the organic electroluminescence device, and the distribution of the intensity of light discharged out of the substance layer is increased after passing through the second class intermediate layer; or a third class intermediate layer is located outside the light emitting substance layer in the direction opposite to the boundary for discharge of light out of the organic electroluminescence device, and the light discharged out of the substance layer to the third class intermediate layer by the third class intermediate layer is reflected; or, the light emitting substance layer is separated by a partition having a contact surface unparallel to the boundary for discharging light out of the organic electroluminescence device, and the partition is formed along the height crossing the light emitting layer or is formed on a layer or substrate other than light emitting layer.
The organic electroluminescence device and photoelectron device using said device is characterized in that the partition is formed in the direction parallel to the direction of polarization having occurred inside the device film surface but not in the direction vertical to the direction of polarization.
The organic electroluminescence device and photoelectron device using said device is characterized in that the direction showing one half of the luminance in the direction of 0 deg. with respect to the direction of the normal to the light discharge plane is 40 deg. or more.
The organic electroluminescence device and photoelectron device using said device is characterized in that the light emitting substance layer contains an organic compound of ionic nature.
The organic electroluminescence device and photoelectron device using said device is characterized in that an organic compound having the structure of Chemical Formula 1 contained therein. 
The organic electroluminescence device and photoelectron device using said device is characterized in that light is taken out of the boundary opposite to the substrate with respect to the light emitting substance layer.
The organic electroluminescence device and photoelectron device using said device is characterized in that the organic electroluminescence device is formed on the substrate where an amorphous silicon thin film transistor or polycrystalline silicon thin film transistor is formed, or on the substance where an organic thin film transistor is formed.
The organic electroluminescence device and photoelectron device using said device is characterized in that the organic electroluminescence device is integrated after having been formed separately from the substrate where an amorphous silicon thin film transistor or polycrystalline silicon thin film transistor or a substrate where the organic thin film transistor is formed.
A still further embodiment of the present invention provides an organic electroluminescence device and photoelectron device using the device characterized by a three dimensional display, which can be viewed by the user wearing glasses which allow the light emitted from the organic electroluminescence device to reach each of the right and left eyes of the user separately in conformity to the difference in polarization, and a three-dimensional display viewing system wherein three-dimensional video information is filmed to provide the three-dimensional display, and image processing is performed, whenever required, so that the information is converted into recording or broadcasting media which are sent to the user.
A still further embodiment of the present invention provides an organic electroluminescence device and photoelectron device using the device characterized by a three dimensional display which can be viewed by the user wearing glasses which allow the light emitted from the organic electroluminescence device to reach each of the right and left eyes of the user separately in conformity to the difference of polarization, and an encryption display viewing system wherein signals are divided to ensure that the normal image is viewed by the user without said glasses, but different information is displayed for the user wearing said glasses due to a difference in polarization.
A still further embodiment of the present invention provides an organic electroluminescence device and photoelectron device using the device characterized by a display viewing system wherein normal display viewing, three-dimensional display viewing and encryption display viewing can be separated on one display screen.
A still further embodiment of the present invention provides an organic electroluminescence device and photoelectron device using the device characterized by a display viewing system; wherein normal display viewing, three-dimensional display viewing and encryption display viewing can be selectively used according to an agreement between the image provider and the user, and the function of the decoder to permit reading by the user can be switched in conformity with said selection, or the decoder selection and time period can be changed according to the agreement as required even if the recording or broadcasting media supplied by the image provider are the same. Furthermore, the agreement can be signed up, modified or canceled by controlling the setup conditions of said display viewing system of the user through the Internet whenever required.
The organic electrolurninescence device allows the holes to be injected from the anode electrode and the electrons to be injected from the cathode electrode for the light emitting layer, including the organic light emitting molecules, and permits light to be emitted by recombination of the holes and electrons inside said light emitting layer, where the layer can be either single or multiple layer. In addition to the organic light emitting molecule which emits light by recombination of a hole and electron, said light emitting layer can contain a fluorescent substance (or phosphorescent substance) which absorbs the light emitted from said organic light emitting molecule to emit another beam of light. Furthermore, said light emitting layer can contain a hole transport substance or electron transport substance which facilitates movement of the hole or electron inside said light emitting layer. Said light emitting layer can also incorporate a capturing substance or electron capturing substance which captures the hole or electron at a specific spatial position or reduces the transportability. Furthermore, said organic light emitting molecule, fluorescent substance (or phosphorescent substance), hole transport substance, electron transport substance, hole capturing substance and electron capturing substance can be incorporated in one and the same layer, or can be dispersed and contained in different layers. Even when these constituting substances are separated, multiple layers containing them are formed, and such multiple layers are collectively called a light emitting layer in the description of the present invention.
A hole injection layer or electron injection layer to improve the hole or electron injection efficiency may be installed between said light emitting layer of the present invention and said anode or said cathode to inject holes or electrons to said light emitting layer.
Substrates to hold said light emitting layer, anode, cathode, hole injection layer and electron injection layer may be installed. Other intermediate layers may be installed whenever required. Such intermediate layers include a reflection mirror to modulate light reflection characteristics, a partial transmission mirror, a filter to allow specific light to pass through, a light switch to adjust the ongoing light timing, a wavelength plate to adjust light phase characteristics, a dispersion plate to disperse light in the ongoing direction, and a protective film to prevent device constituting substances from being deteriorated by external light, heat, oxygen or water. These intermediate layers can be installed between said light emitting layer, anode, cathode, hole injection layer, electron injection layer and substrate or on their outside, as required, based on the specifications which protect device characteristics against deterioration. Of these layers, the layer as the top surface from which light is discharged out of the organic electroluminescence device will be called a top discharge layer.
The transition dipole moment in the description of the present invention denotes the transition moment as a non-diagonal element out of the transition dipole matrix elements constituting the electric dipole transition by molecular light. Its absolute value is proportional to oscillator intensity, and defines the directions of light radiation and polarization. To put it more specifically (according to xe2x80x9cUnabridged Dictionary of Applied Physicsxe2x80x9d edited by the Japan Society of Applied Physics, Ohm Publishing Co., Ltd., 1998), the term electric dipole denotes a pair of electrical charges having different symbols located a certain distance away from each other. By contrast, the transition dipole matrix element appears when calculating the transition probability between quantum states accompanied by dipole radiation. It denotes the matrix element of the initial state xcexa8i and final state xcexa8f of the dipole moment as an operator.
Pfi= less than xcexa8f|p|xcexa8i greater than 
Transition between the electron states having different initial and final states (i.e. xcexa8ixe2x89xa0xcexa8f) is called the transition moment. Assume in this case that the electron mass is mo, the frequency of transition energy between electron states is xcfx89fi, and the value obtained by dividing the black Planck""s constant by 2xcfx80is xcex7. Then the oscillator intensity is expressed by the following formula:   Ffi  =            2                        m          o                ⁢        η        ⁢                  xe2x80x83                ⁢                  ω          fi                      ⁢          "LeftBracketingBar"               less than                   ϕ          f                    "RightBracketingBar"        ⁢    p    ⁢          "LeftBracketingBar"                        ϕ          i                 greater than         2            
The electroluminescence material which can be used in accordance with the present invention includes various metal complex type light emitting materials (8-quinolinol, benzooxazol, azomethine, flavone, etc. as ligand, and Al, Be, Zn, Ga, Eu, Pt, etc. as central metal) and fluorescent pigment based light emitting material (oxadiazole, pyrazoline, distyryl arylene, cyclopentadiene, tetraphenyl butadiene, bisstyryl anthoracene, perylene, phenanthrene, oligothiophene, pyrazoloquinoline, thiadiazopyridine, laminated perovskite, p-sexiphenyl, Spiro compound, etc.). Or, it is also possible to use various types of high molecule materials (polyphenylene vinylene, polyvinyl carbazole, polyfluorene, etc.) as the light emitting material, or to use the non-light emitting high molecular material (polyethylene, polystyrene, polyoxyethylene, polyvinyl alcohol, polymethyl methacrylate, polymethyl acrylate, polyisoprene, polyimide, polycarbinate, etc.) as a matrix, thereby blending and copolymerizing various types of light emitting materials or fluorescent materials. It is also possible to use various organic holes or an electron transport material (triphenylamine, etc.) as an intermediary. Furthermore, various types of hole or electron injection layers (e.g. Li, Ca, Mg, Cs, CuPc, etc.) can be used as the intermediary, Materials can be used in conformity to the device configuration as required. The preferred compound among various types of said organic electroluminescence material is organic compound having a transition dipole moment with a great light emitting power in the molecular structure capable of anisotropic light emission. It is preferred that a molecular structure which facilitates control of the orientation state of the part of the molecule or molecular skeleton is present in the molecule skeleton itself having the transition dipole moment related to such light emission or in the part of the molecule other than said molecular skeleton.
An organic electroluminescence device according to the present invention can be created using various thin film formation techniques, such as a spin coating method, coating method, casting method, sputtering method, vacuum evaporation method, molecule beam vacuum evaporation method, liquid phase epitaxial method, atomic layer epitaxial method, roll method, screen printing method, ink jetting method, field polymerization method, rubbing method, spraying method, water surface development method and Langmuir-Blodgett film method.
The following methods can be used to control orientation of the transition dipole moment related to said light emission with a desired orientation. There is a spin coating method based on the centrifugal force during film formation, an axial spin coating method to turn the substrate about its rotary axis, a specific direction spraying or high-speed substrate movement/rotation method, a pull-put method, an injection method, a roll orientation method where simultaneous orientation is carried out in the possible film forming process by orientation of the molecular skeleton including a specified transition dipole moment in a specific direction in the film formation process or other molecular skeletons under greater orientation restrictions, a spin coating method after formation of thin film, a rubbing method, an electric field application method, a magnetic field application method, an optical orientation method and a thermal annealing method where orientation is carried out after film formation.
In order to promote orientation during or after film formation, it is also possible to use a crystalline substrate where the substrate itself has an orientation restricting force, an oriented film coated substrate and substrates provided with physical or chemical surface treatment. Furthermore, the molecular skeleton in the compound suited to orientation treatment is preferred to exhibit liquid crystal properties in the orientation process. It is also effective to fix the state of orientation by cooling the sample below the glass transition temperature after orientation or by formation of new chemical bondage between molecules through reaction by light and heat.
Furthermore, the substrate used can also be a substrate comprising such inorganic substances as glass, silicon and gallium arsenide, a substrate comprising such organic substances as polycarbonate, polyethylene, polystyrene, polypropylene and polymethyl methacrylate, or a substrate comprising a combination of organic and inorganic substances. These substrates can be formed by grinding and injection molding after the material is taken out of the matrix. The partition and the second, third or fourth class intermediate layer according to the present invention can be formed inside the substrate or on the surface thereof in the process. After that, the intended organic electroluminescence layer can be formed. In addition, to control the state of light emission, it is possible to use the substrate where a thin film transistor is formed. An organic electroluminescence layer can be formed on the substrate where such a thin film transistor is formed. Or it is also possible to separately produce the substrate where a thin film transistor is formed and the substrate where an organic electroluminescence layer is formed. Then, these substrates can be integrated into one piece.
The organic electroluminescence device of the present invention allows use of various precision processing techniques in order to produce the optical device structure required in the device formation process. Such processing technique includes precision diamond cutting, laser cutting, etching, photolithography, reactive ion etching and focused ion beam etching. It is also possible to lay out multiple pre-processed organic electroluminescence devices, to create multi-layered structures thereof, to connect them by an optical waveguide or seal them in the current state.
The device can be stored in a vessel filled with inert gas or liquid. It can also be provided with a cooling or heating mechanism to adjust the working environment. The vessel can be made of such metals as copper, silver, stainless steel, aluminum, brass, iron and chromium, their alloys, composite materials formed by dispersing such metals in high molecular materials such as polyethylene and polystyrene, and ceramic materials. In addition, a heat insulating layer, foamed styrene, porous ceramic, glass fiber sheet and paper can also be used. Especially, coating can be provided to prevent dew condensation. The inert liquid to be filled inside can be water, heavy water, alcohol, wax of a low melting point, mercury and the liquid mixture thereof. Inert gas to be filled inside can be helium, argon, nitrogen, etc. A desiccator can be placed to reduce humidity in the vessel.
The organic electroluminescence device of the present invention can be treated for improvement of its external appearance, characteristics and service life after formation of the product. Such post-treatment includes thermal annealing, application of radiation, irradiation with an electron beam, light, radio waves, magnetic beam and supersonic waves. Furthermore, the organic electroluminescence device can be made composite in various ways, for example, by adhesion, fusion, electrodeposition, vacuum evaporation, crimping, dyeing, formation of melting, kneading, press molding, coating, and other appropriate means in conformity to particular applications or purposes.
The organic electroluminescence device of the present invention can be packaged with a high density at a position close to the electronic circuit for drive, and can be integrated with the interface or antenna for exchange of signals with the outside.